Pellet cooling waste heat recovery device and waste heat recovery method

Abstract

The invention discloses a pellet cooling waste heat recovery device and a waste heat recovery method, and solves the technical problems of poor waste heat recovery effect, high operation cost and the like. The cooling waste heat recovery device comprises a roasting furnace used for firing pellets; the waste heat recovery boiler is arranged on the side of the roasting furnace; and the conveying mechanism is arranged between the roasting furnace and the waste heat recovery boiler and used for conveying pellets discharged from the discharging end of the roasting furnace to the feeding end of the waste heat recovery boiler. The system has the advantages that the occupied area is saved, the arrangement is compact, the operation cost is reduced, the heat loss is reduced, and the waste heat recovery effect is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pellet waste heat recovery, and in particular relates to a pellet cooling waste heat recovery device and a waste heat recovery method. Background Art

[0002] The cooling of pellets is one of the more important links in the vertical furnace production process. Generally, the temperature of the pellets that pass through the vertical furnace roasting zone and the soaking zone and reach the cooling zone is generally above 1000℃. The temperature of the pellets discharged after the first cooling in the furnace is still as high as 600-800℃. The first cooling cannot cool the hot pellets to below 150℃, and the pellets usually need to be cooled twice.

[0003] At present, the secondary cooling process of pellets fired in a vertical furnace usually adopts a belt cooler. After the hot pellets are discharged from the vertical furnace, they are sent to the belt cooler, where they are cooled by blowing air while being transported. At the same time, a flue gas collection hood is set above the belt cooler to recover the heat of the high-temperature flue gas generated during the cooling of the pellets.

[0004] However, the use of belt coolers to cool pellets requires a large floor space and requires additional blowers, which increases operating costs. At the same time, the use of flue gas hoods to recover heat from the high-temperature flue gas generated during the cooling of pellets poses a risk of heat waste and affects the waste heat recovery effect, which needs to be improved. Summary of the invention

[0005] In order to solve all or part of the above problems, the purpose of the present invention is to provide a pellet cooling waste heat recovery device and a waste heat recovery method, which has the advantages of saving floor space, compact layout, reducing operating costs, reducing heat loss, and improving waste heat recovery effect.

[0006] In a first aspect, the present invention provides a pellet cooling waste heat recovery device, comprising:

[0007] Roasters, used to burn pellets;

[0008] A waste heat recovery boiler is arranged on the side of the roasting furnace;

[0009] The conveying mechanism is arranged between the roasting furnace and the waste heat recovery boiler, and is used to transport the pellets discharged from the discharge end of the roasting furnace to the feed end of the waste heat recovery boiler.

[0010] Optionally, the cooling waste heat recovery device further includes:

[0011] The conveyor belt is arranged below the waste heat recovery boiler and is used to transport the pellets discharged from the discharge end of the waste heat recovery boiler to a desired location.

[0012] Optionally, the cooling waste heat recovery device further includes:

[0013] The user network group is connected to the steam pipeline of the waste heat recovery boiler.

[0014] Optionally, the conveying mechanism includes a conveying hopper and a thermal insulation lifting mechanism, the conveying hopper is located directly below the discharge end of the roasting furnace, and the feeding end of the thermal insulation lifting mechanism is located directly below the conveying hopper. The thermal insulation lifting mechanism is used to insulate the pellets and convey the pellets to the feeding end of the waste heat recovery boiler.

[0015] Optionally, the waste heat recovery boiler adopts a vertical furnace structure.

[0016] Optionally, the roasting furnace is a roasting vertical furnace.

[0017] In a second aspect, the present invention provides a pelletizing waste heat recovery method, using a cooling waste heat recovery device, comprising the following steps:

[0018] S1, firing the pellets through a roaster;

[0019] S2, transporting the fired pellets to the feed end of the waste heat recovery boiler through a conveying mechanism;

[0020] S3, after the pellets enter the waste heat recovery boiler, the pellets heat the cooling medium in the waste heat recovery boiler, so that hot steam is generated in the waste heat recovery boiler, and the pellets are cooled at the same time;

[0021] S4, discharging the hot steam generated in the waste heat recovery boiler through a steam pipe for use by users, thereby realizing waste heat recovery and utilization;

[0022] S5, discharging the pellets cooled in the waste heat recovery boiler.

[0023] Optionally, in S2, the pellets are transported in an insulated manner by an insulated lifting mechanism to ensure the temperature of the pellets.

[0024] Optionally, in S4, the hot steam generated in the waste heat recovery boiler is connected to the user network group through a steam pipeline for use by users.

[0025] It can be seen from the above technical scheme that the pellet cooling waste heat recovery device and waste heat recovery method provided by the present invention have the following advantages:

[0026] The cooling waste heat recovery device replaces the traditional belt cooler with a waste heat recovery boiler, which can not only cool the pellets, but also directly transfer the heat energy of the pellets to the cooling medium in the boiler through the heating surface of the waste heat recovery boiler. The hot steam generated in the boiler can be directly used by users, which can avoid the waste caused by secondary energy transfer and improve the waste heat recovery effect. At the same time, using a waste heat recovery boiler to replace the traditional belt cooler reduces the floor space, makes the layout of the cooling waste heat recovery device more compact, and reduces the operating cost.

[0027] Other features and advantages of the present invention will be set forth in the description which follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0029] Figure 1 This is a schematic diagram of the structure of a pellet cooling waste heat recovery device in Example 1 of the present invention;

[0030] Figure 2 This is a flow chart of the pellet waste heat recovery method in Example 2 of the present invention.

[0031] Description of reference numerals:

[0032] 1. Roasting furnace; 2. Waste heat recovery boiler; 3. Conveying mechanism; 31. Conveying hopper; 32. Insulation lifting mechanism; 4. Conveyor belt; 5. User network group. DETAILED DESCRIPTION

[0033] To make the purpose, technical solution and advantages of the present invention more clear, the embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other arbitrarily without conflict.

[0034] Example 1

[0035] like Figure 1The embodiment 1 of the present invention is shown, in which a pellet cooling waste heat recovery device is disclosed, including a roasting furnace 1, a waste heat recovery boiler 2, a conveying mechanism 3, a conveyor belt 4 and a user network group 5. The roasting furnace 1 is used to burn pellets, and the waste heat recovery boiler 2 is arranged on the side of the roasting furnace 1, and is used to cool the pellets and recover waste heat. The conveying mechanism 3 is arranged between the roasting furnace 1 and the waste heat recovery boiler 2, and is used to transport the pellets discharged from the discharge end of the roasting furnace 1 to the feed end of the waste heat recovery boiler 2. The conveyor belt 4 is arranged below the waste heat recovery boiler 2, and is used to transport the pellets discharged from the discharge end of the waste heat recovery boiler 2 to the desired location, and the user network group 5 is connected to the steam pipeline of the waste heat recovery boiler 2.

[0036] The pellets are fired by the roasting furnace 1, and the fired pellets are discharged to the conveying mechanism 3 through the discharge end of the roasting furnace 1, and then the conveying mechanism 3 conveys the pellets to the feeding end of the waste heat recovery boiler 2. When the pellets enter the waste heat recovery boiler 2, the pellets exchange heat with the cooling medium in the waste heat recovery boiler 2 to achieve cooling of the pellets. At this time, hot steam is generated in the waste heat recovery boiler 2, and the hot steam enters the user network group 5 through the steam pipe of the waste heat recovery boiler 2 for use by the user network group 5 or power generation, thereby realizing waste heat recovery. When the pellets are cooled to a preset temperature, the pellets are discharged to the conveyor belt 4 through the discharge end of the waste heat recovery boiler 2, and then the conveyor belt 4 can transport the pellets to the next process.

[0037] The pellet cooling waste heat recovery device in this embodiment replaces the traditional belt cooler with the waste heat recovery boiler 2, which can not only achieve the cooling of the pellets, but also directly transfer the heat energy of the pellets to the cooling medium in the boiler through the heating surface of the waste heat recovery boiler 2, and the hot steam generated in the boiler can be directly used by the user, which can avoid the waste caused by the secondary transfer of energy and improve the waste heat recovery effect. At the same time, the waste heat recovery boiler 2 is used to replace the traditional belt cooler to reduce the floor space, making the layout of the cooling waste heat recovery device more compact and reducing the operating cost.

[0038] In one embodiment, Figure 1 As shown, the conveying mechanism 3 includes a conveying hopper 31 and a heat preservation and lifting mechanism 32. The conveying hopper 31 is located directly below the discharge end of the roasting furnace 1, and the feeding end of the heat preservation and lifting mechanism 32 is located directly below the conveying hopper 31, so that the pellets can smoothly enter the heat preservation and lifting mechanism 32. The heat preservation and lifting mechanism 32 is used to keep the pellets warm and convey the pellets to the feeding end of the waste heat recovery boiler 2 to reduce the risk of heat loss of the pellets.

[0039] In this embodiment, the heat preservation and lifting mechanism 32 can use a mechanical transport vehicle, and a heating component is arranged on the outside of the transport vehicle to ensure the temperature of the pellets. Of course, the heat preservation and lifting mechanism 32 can also use a spiral elevator, and a heating component is arranged on the outer cylinder of the spiral elevator to ensure the heat preservation and transportation function of the pellets. The heat preservation and lifting mechanism 32 can also use a mechanical conveyor belt with a heat preservation shell to ensure the temperature of the pellets.

[0040] In one embodiment, Figure 1 As shown, the waste heat recovery boiler 2 adopts a vertical furnace structure to achieve sufficient heat exchange, thereby improving the cooling effect. The roasting furnace 1 also adopts a roasting vertical furnace to ensure the thermal efficiency of the roasting furnace 1 and effectively utilize heat.

[0041] Example 2

[0042] like Figure 2 The example 2 of the present invention is shown, and a method for recovering waste heat from pellets is disclosed in the example. The method uses the cooling waste heat recovery device in the example and includes the following steps.

[0043] S1, firing pellets through roasting furnace 1;

[0044] S2, transporting the fired pellets to the feed end of the waste heat recovery boiler 2 through the conveying mechanism 3;

[0045] S3, after the pellets enter the waste heat recovery boiler 2, the pellets heat the cooling medium in the waste heat recovery boiler 2, so that hot steam is generated in the waste heat recovery boiler 2, and the pellets are cooled at the same time;

[0046] S4, the hot steam generated in the waste heat recovery boiler 2 is discharged through the steam pipe for use by users, thereby realizing waste heat recovery and utilization;

[0047] S5, discharging the pellets cooled in the waste heat recovery boiler 2.

[0048] In S2, the pellets are transported in an insulated manner by the insulated lifting mechanism 32 to ensure the temperature of the pellets. In S4, the hot steam generated in the waste heat recovery boiler 2 is connected to the user network group 5 through a steam pipeline for use by users.

[0049] The pellet waste heat recovery method in this embodiment optimizes the firing and cooling process of the pellets, and replaces the traditional belt cooler with the waste heat recovery boiler 2. The heat energy of the pellets is directly transferred to the cooling medium in the boiler through the heating surface of the waste heat recovery boiler 2, and the hot steam generated in the boiler can be directly used by users, which can avoid the waste caused by secondary energy transfer and improve the waste heat recovery and utilization effect.

[0050] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present invention should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0051] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A pellet cooling waste heat recovery device, characterized in that: include: A roasting furnace (1) for firing pellets; A waste heat recovery boiler (2) is arranged on the side of the roasting furnace (1); The conveying mechanism (3) is arranged between the roasting furnace (1) and the waste heat recovery boiler (2), and is used to transport the pellets discharged from the discharge end of the roasting furnace (1) to the feed end of the waste heat recovery boiler (2).

2. The cooling waste heat recovery device according to claim 1, characterized in that: The cooling waste heat recovery device also includes: The conveyor belt (4) is arranged below the waste heat recovery boiler (2) and is used to transport the pellets discharged from the discharge end of the waste heat recovery boiler (2) to a desired location.

3. The cooling waste heat recovery device according to claim 1, characterized in that: The cooling waste heat recovery device also includes: The user network group (5) is connected to the steam pipeline of the waste heat recovery boiler (2).

4. The cooling waste heat recovery device according to claim 1, characterized in that: The conveying mechanism (3) comprises a conveying hopper (31) and a heat-insulating lifting mechanism (32); the conveying hopper (31) is located directly below the discharge end of the roasting furnace (1); the feed end of the heat-insulating lifting mechanism (32) is located directly below the conveying hopper (31); the heat-insulating lifting mechanism (32) is used to keep the pellets warm and to convey the pellets to the feed end of the waste heat recovery boiler (2).

5. The cooling waste heat recovery device according to claim 1, characterized in that: The waste heat recovery boiler (2) adopts a vertical furnace structure.

6. The cooling waste heat recovery device according to claim 1, characterized in that: The roasting furnace (1) is a roasting vertical furnace.

7. A pelletizing waste heat recovery method, using the cooling waste heat recovery device according to any one of claims 1 to 6, characterized in that: The steps include: S1, firing pellets in a roasting furnace (1); S2, transporting the fired pellets to the feed end of the waste heat recovery boiler (2) through a conveying mechanism (3); S3, after the pellets enter the waste heat recovery boiler (2), the pellets heat the cooling medium in the waste heat recovery boiler (2) so that hot steam is generated in the waste heat recovery boiler (2), and the pellets are cooled at the same time; S4, discharging the hot steam generated in the waste heat recovery boiler (2) through a steam pipe for use by users, thereby realizing waste heat recovery and utilization; S5, discharging the pellets cooled in the waste heat recovery boiler (2).

8. The waste heat recovery method according to claim 7, characterized in that: In S2, the pellets are transported in an insulated manner by an insulated lifting mechanism (32) to ensure the temperature of the pellets.

9. The waste heat recovery method according to claim 7, characterized in that: In S4, the hot steam generated in the waste heat recovery boiler (2) is connected to the user network group (5) through a steam pipeline for use by users.

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